High rate packet data (HRPD for short) network technology ensures that a wireless network based on CDMA access system better adapts to various new services in the future, such as VoIP, multimedia service and etc. In the access network technologies, there are various relevant flows for supporting the technology of Version A of HRPD air interface.
FIG. 1 shows an existing call flow for releasing HRPD session, which is initiated by an access terminal (AT for short) or an access network (AN for short), and the process of which will result in the release of the packet data session if it exists. Assuming the A8 connection has been established, the flow shown in FIG. 1 applies to either the session control and mobility management is located in AN or the packet control function entity (PCF for short). As shown in FIG. 1, the flow includes the following steps:
S102: The AT or AN initiates a HRPD session release.
S104: After closing the HRPD session with AT, AN sends to PCF an A9-release-A8 message with the cause value of “normal call releasing”, requesting that PCF releases all associated dedicated resources and all associated A10 connections. The AN starts a timer Tre19.
S106: the PCF sends to PDSN an A11 registration request message with the lifetime of 0 so as to close the A10 connections. Active Stop accounting records are included in the message for all IP flows in the activated state associated with the AT. The PCF starts a timer Tregreq.
S108: the PDSN stores the accounting data for a further processing and completes the release of the A10 connections with A11-registration response message as the response. The PCF stops the timer Tregreq.
S110: PCF sends to An A9-release-A8 complete message to AN, AN stops the timer Tre19.
FIG. 2 shows a call flow for releasing HRPD session, which is initiated by the AT or AN and the process of will result in the release of the packet data session if it exists. Assuming the A8 connection is not established, the flow shown in FIG. 2 applies to the session control and mobility management is located in AN. As shown in the FIG. 2, the flow includes the following steps:
S202: the AT or AN initiates the release of the HRPD session.
S204, when closing the HRPD session with the AT, the AN sends to the PCF an A9-update-A8 message with the cause value of “Power down from dormant state”, requesting the PCF to release the related specific resources and the A10 connection. The AN starts a timer Tupd9.
S206: the PCF sends to the PDSN an A11-registration request message with the lifetime of 0 so as to close the A10 connections. The PCF starts the timer Tregreq.
S208: the PDSN completes the release of the A10 connections with the A11-registration response message as the response. The PCF stops the timer Tregreq upon receiving such message.
S210: the PCF sends the A9-update-A8 Ack message to the AN. The AN stops the timer Tupd9 upon receiving such message.
The respective reasons for releasing the HRPD session in the above flows are embodied in the messages of A9-release-A8 and the A9-update-A8. That is, in the case that the A8 connection exists, the cause value is ‘normal call release’; and in the case that the A8 connection does not exist, the cause value is ‘Power down from dormant state’.
In fact, the causes for closing a session is more than the above two reasons. When the HRPD session exists, the network can reauthenticate the AT any time, so as to ensure that valid users can enjoy services and to prevent unauthorized users from using services. Once the reauthentication of the user fails, the AT and AN must release the HRPD session connection immediately. Therefore, the failure of reauthentication of a terminal user is also an important situation which causes the release of the corresponding session.